Question

Carefully look at this velocity time graph which line shows that the object is at constant velocity

Answer 1

The velocity can be defined as the ratio of the total displacement to the total time duration in which the object covers the displacement.

Thus the velocity is given by,

`v=(\Delta d)/(\Delta t)`

Where Δd is the displacement and Δt is the time duration.

This is nothing but the slope of a position-time graph. Thus the slope of the position-time graph gives us the velocity of the object.

The velocity of the object will be the same if the slope of the line that represents the object's motion, in the given time is constant.

Thus any straight line in the position-time graph represents the constant velocity except for the horizontal lines. Because, the horizontal line implies that the position of the object is not changing with time, which means that the velocity is zero in that stretch of time.

Thus the correct answer is option 2, A and C